| For the music band, see Gamma Ray (band).Gamma rays are generally characterized as electromagnetic radiation having the highest frequency and energy, and also the shortest wavelength, within the electromagnetic spectrum, i.Due to their high energy content, they can cause serious damage when absorbed by living cells.Uses
3 Health effect
3.Shielding gamma rays requires large amounts of mass.The higher the energy of the gamma rays, the thicker the shielding required.Materials for shielding gamma rays are typically measured by the thickness required to reduce the intensity of the gamma rays by one half (the half value layer or HVL).For example, gamma rays that require 1 cm (0.The total absorption coefficient of aluminium (atomic number 13) for gamma rays, plotted versus gamma energy, and the contributions by the three effects.The total absorption coefficient of lead (atomic number 82) for gamma rays, plotted versus gamma energy, and the contributions by the three effects.Here, the photo effect dominates at low energy.When a gamma ray passes through matter, the probability for absorption in a thin layer is proportional to the thickness of that layer.The exponential absorption holds only for a narrow beam of gamma rays.If a wide beam of gamma rays passes through a thick slab of concrete, the scattering from the sides reduces the absorption.In passing through matter, gamma radiation ionizes via three main processes: the photoelectric effect, Compton scattering, and pair production.Photoelectric Effect: This describes the case in which a gamma photon interacts with and transfers its energy to an atomic electron, ejecting that electron from the atom.Compton scattering is thought to be the principal absorption mechanism for gamma rays in the intermediate energy range 100 keV to 10 MeV.MeV) appears as the kinetic energy of the pair and the recoil nucleus.At the end of the positron's range, it combines with a free electron.Gamma decay
Gamma rays are often produced alongside other forms of radiation such as alpha or beta.It can then jump down to a lower level by emitting a gamma ray in much the same way that an atomic electron can jump to a lower level by emitting visible light or ultraviolet radiation.UV rays are all forms of electromagnetic radiation.Gamma rays are the most energetic.An example of gamma ray production follows.Gamma rays of 1.Another example is the alpha decay of 241Am to form 237Np; this alpha decay is accompanied by gamma emission.Pt), the gamma emission spectrum is complex, revealing that a series of nuclear energy levels can exist.Image of entire sky in 100 MeV or greater gamma rays as seen by the EGRET instrument aboard the CGRO spacecraft.Bright spots within the galactic plane are pulsars while those above and below the plane are thought to be quasars.Hence from beta decay alone it is not possible to probe the different energy levels found in the nucleus.Here, a correction for the energy lost by the recoil of the nucleus is made and the exact conditions for gamma ray absorption through resonance can be attained.This is similar to the Franck Condon effects seen in optical spectroscopy.Because the wavelength of gamma radiation is so short, a single incident photon can impart significant damage to a living cell.This property means that gamma radiation is often used to kill living organisms, in a process called irradiation.The beams are aimed from different angles to focus the radiation on the growth while minimizing damage to the surrounding tissues.The Moon as seen in gamma rays by the Compton Gamma Ray Observatory.Surprisingly, the Moon is actually brighter than the Sun at gamma ray wavelengths.Gamma rays are also used for diagnostic purposes in nuclear medicine.Gamma ray detectors are also starting to be used in Pakistan as part of the Container Security Initiative (CSI).Health effect
The gamma rays are the most dangerous form of radiation emitted by a nuclear explosion because of the difficulty in stopping them.They are also the smallest ray in the electromagnetic spectrum.Natural exposure to gamma rays is about 1 to 2 mSv a year, and the average total amount of radiation received in one year per inhabitant in the USA is 3.Sv on the skin of the back.For low dose exposure, for example among nuclear workers, who receive an average radiation dose of 19mSv, the risk of dying from cancer (excluding leukemia) increases by 2 percent.This page was last modified 02:09, 10 January 2008.See Copyrights for details.Drawing of a massive star collapsing to form a black hole.Energy released as jets along the axis of rotation forms a gamma ray burst.They are flashes of gamma rays emanating from seemingly random places in deep space at random times.All known GRBs originate from outside our own galaxy; though a related class of phenomena, SGR flares, are associated with Galactic magnetars.The sources of most GRBs are billions of light years away.Though the short duration of a gamma ray burst would limit the immediate damage to life, a nearby burst might alter atmospheric chemistry by reducing the ozone layer and generating acidic nitrogen oxides.These atmospheric changes could ultimately cause severe damage to the biosphere.Discovery and history
1.Vela and the discovery of GRBs
1.Distance scale and energetics
2.Progenitors: what makes GRBs explode?US Vela nuclear test detection satellites.The United States suspected that the USSR might attempt to conduct secret nuclear tests after signing the Nuclear Test Ban Treaty in 1963.BATSE
The presence of GRBs was confirmed later by many space missions such as Apollo and the Soviet Venera probes.To explain these events, many speculative theories were advanced, most of which posited nearby Galactic sources.The separation is not absolute and the populations overlap observationally, but the distinction suggests two different classes of progenitors.Prior to the launch of BATSE, the distance scale to GRBs was completely unknown.Theories for the location of these events ranged from the outer regions of our own solar system to the edges of the known universe.Not only are GRBs extragalactic events, but they are also observable to the limits of the visible universe; a typical GRB has a redshift of at least 1.GRBs may actually originate from even higher redshifts.GRB Jets: collimated emission
Many GRBs have been observed to undergo a jet break in their light curve, during which the optical afterglow quickly changes from slowly fading to rapidly fading as the jet slows down.The jet opening angle (degree of beaming), however, varies greatly, from 2 degrees to more than 20 degrees.Bright hypernovae do in fact appear to accompany some GRBs.While the collapsar model has enjoyed a great deal of success, many other models exist that are still seriously considered.The different models are not mutually exclusive, and it is possible that different bursts have different progenitors.GRBs must explain not only the energy source, but also the physical process for generating an emission of gamma rays which matches the durations, light spectra, and other characteristics of observed GRBs.Mass extinction on Earth
Research has been conducted to investigate the consequences of Earth being hit by a beam of gamma rays from a nearby (about 500 light years) gamma ray burst.This is motivated by the efforts to explain mass extinctions on Earth and estimate the probability of extraterrestrial life.Earth, the other half being in its shadow.However, the damage from a gamma ray burst would probably be significantly greater than a supernova at the same distance.The scientists do not have direct evidence to suggest that such a burst resulted in the ancient extinction, rather the strength of their work is their atmospheric modeling, essentially a "what if" scenario.With the ozone layer damaged, ultraviolet radiation from the Sun would kill much of the life on land and near the surface of oceans and lakes, disrupting the food chain.Milky Way galaxy are indeed rare, NASA scientists estimate that at least one nearby event has probably hit the Earth in the past billion years.Milky Way galaxy hosting a GRB was estimated at less than 0.Notable GRBs
GRBs of significant historical or scientific importance include:
670702: The first GRB ever detected.The first GRB with a successfully detected afterglow.The location of the afterglow was coincident with a very faint galaxy, providing strong evidence that GRBs are extragalactic.The first GRB with a measured redshift (distance), 0.This confirmed unambiguously that GRBs are extragalactic.The first GRB with an observed associated supernova (1998bw), providing strong evidence of the link between GRBs and supernovae.B: The first short GRB with a host association.Provided evidence that (some) short GRBs, unlike long GRBs, occur in old galaxies and do not have accompanying supernovae.The most distant GRB with a securely measured distance, at a redshift of 6.GRB with an accompanying supernova.Ray Bursts of Cosmic Origin".Astrophysical Journal 413: L101.If two or more GRBs occur on a given day, the name is appended with a letter 'A' for the first burst identified, 'B' for the second and so on.Not all scientists believed in this association at first, and the exact redshift of this particular galaxy was not obtained until many years later.GRB 970508, had a firm absorption redshift of 0.Publications of the Astronomical Society of the Pacific 107: 1167.Astrophysical Journal 641: 989.GRB 050709, a flare but no break".Astrophysical Journal: In publication.Ray Bursts and Explosions in "Failed Supernovae"".Clues about the Central Engine"."Exploding Neutron Stars in Close Binaries".Soviet Astronomy Letters 10: 177.Astrophysical Journal Letters 497: L17.Ray Burst Afterglow Light Curve in the Swift XRT Data".One Less Thing to Worry About.Strong, Klebesadel, and Olson (February 15, 1974)."The Redshift of GRB 970508".Ray Bursts: Evidence for a Standard Energy Reservoir".The Big One That Didn't Get Away.GCN 2053, GRB 030329, optical spectroscopy.GCN 2176, GRB030329 observed as a sudden ionospheric disturbance (SID).Blast hints at black hole birth.MOST DISTANT EXPLOSION DETECTED, SMASHES PREVIOUS RECORD.Strange Exploding Star Unlocks Supernova Secrets (August 30, 2006).Spatially resolved properties of the GRB 060505 host: implications for the nature of the progenitor.These waves are generated by radioactive atoms and in nuclear
explosions.Different wavelengths of light
penetrate the Earth's atmosphere to different depths."Image of light penetration through the atmosphere.""Space Shuttle deploys CGRO."The two round protrusions
are one of CGRO's instruments, called "EGRET".Dissemination Priorities and Inventories
+ USA."Are you sure you want to block this user?Gamma Ray was born.Scheepers lived such a far way away from Hamburg.This meant that they could only do band rehearsals and such on weekends, and this put a major stopper on things.Since Scheepers had auditioned for the job as vocalist for Judas Priest, and his chances at getting the spot were considered pretty good (in the end he was among the last three candidates), Hansen asked him if he really felt that staying with Gamma Ray was the right thing to do.The two decided that it would be for the best if Scheepers left the band, and so, with no hard feelings on either side, Scheepers (today Primal Fear) left Gamma Ray.On this album there was again a cooperation with vocalist Michael Kiske who did the vocals for one complete song called Time to break free and the chorus of the title track.Critics around the globe were extatic.Kai and Dirk entrench themselves in their studio again in August to record the EP "Silent Miracles", an EP of four wonderful ballads.Henjo Richter was engaged as guitarist, a job he had already done very well on the spanish tour the year before.In early 2004 the band started composing demo material for the new album and finally found itself back in the studio in September to start the recordings of 11 songs, that in contrast to the last two albums, show more complexity and bombast again.DIV td, li, p, div, textarea tablea."Are you sure you want to delete this comment?"Sorry but a friend of mine wrote something really bad about u in their myspace blog, u need to see it.FOUND OUT AWAY TO SEE WHO MY CRUSH IS!DON'T YOU WANNA FIND WHO YOURS IS?YOU GOTTA CHECK THIS OUT, ITS REALLY COOL AND WORKS GREAT!MYCRUSHRESULTSYOU WILL BE ASTONISHED WITH THE RESULTS!Sorry but a friend of mine wrote something really bad about u in their myspace blog, u need to see it.Sorry but a friend of mine wrote something really bad about u in their myspace blog, u need to see it.Holy crap you gotta see these pics from the party I went too..You gotta send my friend a message.She thinks your really CuTE!IT'S A GREAT PLACE TO GO FOR RINGTONES, YOU AND YOUR FRIENDS SHOULD CHECK THIS OUT FOR SURE!Have a great weekend fellow Metallers!!GIFT TO ALL OUR FRIENDS ON MYSPACE,A CHANCE TO LISTEN TO OUR ENTIRE NEW ALBUM "MEDIEVIL" FOR FREE !!!You did a great show in Budapest, loved it (especially the singing part;)!Can't wait to see you in Athens show in a few days!Jungs,das neue Album ist Weltklasse!KNOW its for real now, i'm going to act real fast and grab a few more to wrap up as a gift..KNOW its for real now, i'm going to act quick and get a few more to give to people as a gift..COME TO PUMP UP THE VOLUME!!!!!.COME TO PUMP UP THE VOLUME!!!!!."Urgent Security Alert","Warning: You are submitting information to an outside site.This could be an attempt to steal your username and password.This is not a MySpace login page, please do not enter your MySpace login information (email address or password).Do you wish to continue your form submission?"Id + " Text: " + targetLink.Drums (1998, for 3 shows incl.Ad Lunam)Additional notesGamma Ray was founded by Kai Hansen after drastically leaving Helloween in the late '80s.Array("Introduction to a Mystery","Long or Short Duration?"They were discovered serendipitously in the late 1960s by
U.These satellites carried gamma ray detectors since a nuclear explosion produces gamma rays.As recently as the early 1990s, astronomers didn't even
know if GRBs originated at the edge of our solar system, in our Milky Way Galaxy or incredibly far
away near the edge of the observable Universe.That is, they
didn't know how far away GRBs were to within a factor of a few billion
light years!Hello, you either have JavaScript turned off or an old version of Adobe's Flash Player.This video will appear on your blog shortly.Thank you for sharing your concerns.Content of this nature is not necessarily prohibited on YouTube, however we will review this video and take action as appropriate.Per our Community Guidelines, hate speech is specifically defined in reference to "protected groups."Thank you for sharing your concerns.We can only process copyright complaints submitted by authorized parties in accordance with processes defined in law.There may be significant legal penalties for false notices.Please refer to our Help Center for more information and the form to submit.Change this to see only comments above a certain value.Awesome, I saw Gamma Ray and Helloween this week, they've been touring together.DI like Gamma Ray more then Helloween though, and it's because of the singer.Gamma Ray is the band!Gamma Ray (not gammy gay...The term "infrared" refers to a broad range of frequencies, beginning at the top end of those frequencies used for communication and extending up the the low frequency (red) end of the visible spectrum.The range adjacent to the visible spectrum is called the "near infrared" and the longer wavelength part is called "far infrared".Infrared does not penetrate the atmosphere well, but astronomy in the infrared is carried out with the Spitzer Space Telescope.White light may be separated into its spectral colors by dispersion in a prism.The region just below the visible in wavelength is called the near ultraviolet.It is absorbed very strongly by most solid substances, and even absorbed appreciably by air.The tissue effects of ultraviolet include sunburn, but can have some therapeutic effects as well.The sun is a strong source of ultraviolet radiation, but atmospheric absorption eliminates most of the shorter wavelengths.The term gamma ray is used to denote electromagnetic radiation from the nucleus as a part of a radioactive process.The energy of nuclear radiation is extremely high because such radiation is born in the intense conflict between the nuclear strong force and the electromagnetic force, the two strongest basic forces. |
![Gamma Ray : [1993] Insanity And Genius](/covers/98/983/alb_82641_th.jpg "Gamma Ray : [1993] Insanity And Genius")
